Setting freezer temps with a temp controller

[Inkleg]

Leave it to me to buck the system. I have done it all the ways described until I found these thermowells. I drilled a extra hole in my bucket lid and use it with a #2 stopper. This way I control the exact temperature of the wort. Some temperature probes may no fit, but the ones on a STC-1000 will.

Thermowell.JPG (71.44 KiB) Viewed 1394 times

For those using carboys I think they make a stopper that has two holes and will work, but don't quote me.

[Beer-lord]

I don't feel good enough about drilling into my SS fermenter but I may get the courage one day.

[Kealia]

For those using carboys I think they make a stopper that has two holes and will work, but don't quote me.

Yes, they do - I've seen them. I was thinking about going this route but never pulled the trigger and now I am set in my ways.

[nighthawk]

Reminds me of the mod I did with my lbc. I took the red cap (the one where the drilled stopper and airlock are supposed to go) and I drilled a small hole in the middle and threaded the wire for the temp probe through. I sealed the whole thing up with some food-grade silicone caulking and threw an o-ring on the red cap. Now I can directly measure the temp of my fermenting beer and keep it within 2 degrees of where I want it. And yes, I do use an airlock; I just drilled another hole on the other side of the top and put a rubber grommet in it.

[Beer-lord]

Jeez, went to cold crash tonite, set the Fermostat for 36, came back a few hours later and the airlock was partially frozen though the Fermostat, the stickon thermometer and a separate (but I thought not reliable) thermometer all showed 38. I wonder if the freezer stayed on so long dropping from 68 to 36 it froze up.
Next time I'll do a gradually chill down over a 2-3 day period. Really should have done that anyway but I was lazy.

[RickBeer]

What do you have it set for as far as the temp to shut off, which on a STC-1000 is F2 and most set it for 0.5C? So it gets to 36 but turns off at....

[Beer-lord]

I'm using manual mode and it's set to a 1 degree tolerance so it won't go lower than 35. I have it set to 40 now and it's fine but I really think I should use the gradual temperature decrease next time.

[RickBeer]

Gotchya. With a good freezer, and no heating component, I could see it continue to dip lower as you found.

Yesterday I set mine and put in the 58 degree wort. Hours later it was still 58. I put in the paint can heater (plugged into the STC-1000 heating port) and hours later it was up to 61 or 62. Inside the freezer it was like 80... I unplugged the can.

[Inkleg]

With the freezer trying to chill the large volume of wort, it took the internal temperature below freezing which froze the smaller volume in the airlock. So you're right in thinking it was running longer. Just stop being lazy. I guess if the airlock is frozen there can be no suck back.

[gwcr]

Didn't think about that. Good to know as I'm planning a cold crash on Sunday. Now I won't freak out if that happens.

Edit: might just replace the starsan with vodka. That definitely won't freeze.

[Inkleg]

Good to know as I'm planning a cold crash on Sunday.

You're just running your STC-1000+ in thermostat mode aren't you. Do you have any profiles loaded yet? All my profiles are with ramping enabled, it takes the temperature down over the time I've set, to the temp I've set. Talk about being lazy, I just put the wort in the fridge, push a few bottoms on The Black Box, come back in two weeks and have beer that's fermented and cold crashed.

[Kealia]

This may an advantage, so to speak, about using airtemp instead of the thermowell or clamping a thermometer to the carboy. For fermentation that may be the way to go, but for cold-crashing as long as the air gets down to the thirties the beer temp will follow. And with the differential set it will never too warm before kicking back in. But, by using the air temp you can avoid a situation like this where it's running and won't shut off until it gets to the desired beer temp (or freezes).

[gwcr]

Good to know as I'm planning a cold crash on Sunday.

You're just running your STC-1000+ in thermostat mode aren't you. Do you have any profiles loaded yet? All my profiles are with ramping enabled, it takes the temperature down over the time I've set, to the temp I've set. Talk about being lazy, I just put the wort in the fridge, push a few bottoms on The Black Box, come back in two weeks and have beer that's fermented and cold crashed.

Yep. Just running in thermostat mode right now. Haven't had the time to play with the profiles yet, but it doesn't look too hard to do. That will really come in handy when I try to do a lager later this year.

This may an advantage, so to speak, about using airtemp instead of the thermowell or clamping a thermometer to the carboy. For fermentation that may be the way to go, but for cold-crashing as long as the air gets down to the thirties the beer temp will follow. And with the differential set it will never too warm before kicking back in. But, by using the air temp you can avoid a situation like this where it's running and won't shut off until it gets to the desired beer temp (or freezes).

Good point. May just set to 34, remove the tape and let the probe hang.

[gwcr]

FG 1.010 so I went to crash it last night. Found out something about my freezer. It doesn't like to cycle the compressor too often. I set the temp on the controller to 34 keeping the 1 degree cushion that I had during fermentation, and un-taped the probe from the fermenter so it would just read the ambient temp. Temp dropped quickly, and the compressor turned off. It went through a couple of cycles, then the compressor "locked up" on me. Was clicking like it wanted to come on, but wouldn't cool. After a few moments of rage and wanting to curse out the guy that sold me the freezer, I unplugged it and let it sit for about 5 minutes. Changed the temperature setting to have a 3 degree cushion and plugged it back in. Thankfully it started to cool again. Turned off at the right temp, then I waited for it to warm back up again. 3 degrees later, it kicked back on and is working great still this morning. Guess I'll need to play around with that setting to see if I can drop it to a 2 degree cushion when it's that low of a temp. Anyone else have that kind of issue with your freezer?

[RickBeer]

My STC-1000 stops the compressor from coming on until it's been 3 minutes, which is the default and which nearly everyone seems to use. Does yours have that?

Many also use a 0.5 C variance, so if you set it for 17.5 C it turns off and then doesn't turn back on until 18.0 C. That's less than 1 degree F.